AptBCis1, An Aptamer-Cisplatin Conjugate, Is Effective in Lung Cancer Leptomeningeal Carcinomatosis.

Treatment of lung cancer leptomeningeal carcinomatosis (LM) remains challenging partly due to the biological nature of the blood-brain barrier (BBB). Cisplatin has limited effects on LM, and it is notorious for neurotoxicity. Aptamers are small oligonucleotides considered as antibody surrogates. Here we report a DNA therapeutics, AptBCis1. AptBCis1 is a cisplatin-conjugated, BBB-penetrating, and cancer-targeting DNA aptamer. Its backbone, AptB1, was identified via in vivo SELEX using lung cancer LM orthotopic mouse models. The AptB1 binds to EAAT2, Nucleolin, and YB-1 proteins. Treatment with AptBCis1 1 mg/kg (equivalent to cisplatin 0.35 mg/kg) showed superior tumor suppressive effects compared to cisplatin 2 mg/kg in mice with lung cancer LM diseases. The cerebrospinal fluid platinum concentration in the AptBCis1 group was 10% of that in the cisplatin group. The data suggested the translational potential of AptBCis1 in lung cancer with LM and in cancers in which platinum-based chemotherapy remains as the standard of care.

PINK1-Mediated Inhibition of EGFR Dimerization and Activation Impedes EGFR-Driven Lung Tumorigenesis.

EGFR is established as a driver of lung cancer, yet the regulatory machinery underlying its oncogenic activity is not fully understood. PTEN-induced kinase 1 (PINK1) kinase is a key player in mitochondrial quality control, although its role in lung cancer and EGFR regulation is unclear. In this study, we show that PINK1 physically directly interacts with EGFR via the PINK1 C-terminal domain (PINK1-CTD) and the EGFR tyrosine kinase domain. This interaction constituted an endogenous steric hindrance to receptor dimerization and inhibited EGFR-mediated lung carcinogenesis. Depletion of PINK1 from lung cancer cells promoted EGFR dimerization, receptor activation, EGFR downstream signaling, and tumor growth. In contrast, overexpression of PINK1 or PINK1-CTD suppressed EGFR dimerization, activation, downstream signaling, and tumor growth. These findings identify key elements in the EGFR regulatory cascade and illustrate a new direction for the development of anti-EGFR therapeutics, suggesting translational potential of the PINK1-CTD in lung cancer. SIGNIFICANCE: This study identifies PINK1 as a critical tumor suppressor that impedes EGFR dimerization and highlights PINK1-CTD as a potential therapeutic agent in EGFR-driven lung cancer.

Gas7 knockout affects PINK1 expression and mitochondrial dynamics in mouse cortical neurons.

Dynamic fission and fusion events regulate mitochondrial shape, distribution, and rejuvenation, and proper control of these processes is essential for neuronal homeostasis. Here, we report that Gas7, a known cytoskeleton regulator, controls mitochondrial dynamics within neurons of the central nervous system. In this study, we generated an improved Gas7-knockout mouse and evaluated its mitochondrial phenotype. We first identified Gas7 in mitochondrial fractions from wild-type brain tissue, and observed Gas7 colocalization with mitochondria in primary cortical neurons. In Gas7-deficient brain tissue and neuronal cultures mitochondria were elongated with perinuclear clustering. These morphological abnormalities were associated with increased levels mitochondrial fusion proteins and increased PKA-dependent phosphorylation of Drp-1 in brain tissues, suggesting an imbalance of mitochondrial fusion and fission. Moreover, expression of mitochondrial quality control kinase, PINK1, and PINK1-specific phosphorylation of Mfn-2 (S442), Parkin (S65), and ubiquitin (S65) were all reduced in the knockout cells. Ectopic expression of Gas7 restored mitochondrial morphology and distribution, as well as PINK1 expression in Gas7-null cortical neurons. Collectively, our results introduce a novel role of mouse Gas7 in determining the dynamics, morphology, and intracellular distribution of neuronal mitochondria, which are expected to be required for normal neuronal function.

A Novel TNF-α-Targeting Aptamer for TNF-α-Mediated Acute Lung Injury and Acute Liver Failure.

Rationale: The TNF-α pathway plays as a double-edged sword that simultaneously regulates cell apoptosis and proliferation. The dysregulated TNF-α signaling can trigger cytokine storms that lead to profound cell death during the phase of acute tissue injury. On the other hand, an optimal level of TNF-α signaling is required for tissue repair following the acute injury phase. The TNF-α pathway is commonly upregulated in acute lung injury (ALI) and acute liver failure (ALF). Previous studies investigated the feasibility of adopting protein-based TNF-α blockers as disease modifiers in ALI and ALF, but none of these came out with a positive result. One of the potential reasons that resides behind the failure of the trials might be the long half-life of these inhibitors that led to undesired side effects. Developing alternative TNF-α blockers with manageable half-lives remain an unmet need in this regard. Methods: In the current study, we developed a novel TNF-α-targeting aptamer (aptTNF-α) and its PEG-derivate (aptTNF-α-PEG) with antagonistic functions. We investigated the in vivo antagonistic effects using mouse ALI and ALF models. Results: Our data showed that aptTNF-α possessed good in vitro binding affinity towards human/mouse TNF-α and successfully targeted TNF-α in vivo. In the mouse ALI model, aptTNF-α/aptTNF-α-PEG treatment attenuated the severity of LPS-induced ALI, as indicated by the improvement of oxygen saturation and lung injury scores, the reduction of protein-rich fluid leakage and neutrophil infiltration in the alveolar spaces, and the suppression of pro-inflammatory cytokines/chemokines expressions in the lung tissues. In the mouse ALF model, we further showed that aptTNF-α/aptTNF-α-PEG treatment not only attenuated the degree of hepatocyte damage upon acute injury but also potentiated early regeneration of the liver tissues. Conclusion: The results implicated potential roles of aptTNF-α/aptTNF-α-PEG in ALI and ALF. The data also suggested their translational potential as a new category of TNF-α blocking agent.

Population-Based Cohort Study Reveals Distinct Associations Between Female Lung Cancer and Breast Cancer in Taiwan.

PURPOSE: Associations between Asian lung cancer (LC) and breast cancer (BC) are unknown. This study evaluates associations between LC and BC in the Taiwan population. METHODS: This study was based on the Taiwan National Health Insurance data and Taiwan Cancer Registry. The cohorts included women with newly diagnosed LC or BC between 2000 and 2011 and an age- and sex-stratified random sample as a noncancer comparison cohort during the same period. Cox proportional hazards regression analysis was used to determine the risks. The National Taiwan University Hospital (NTUH) cohort, which comprised patients with confirmed pathology diagnoses of double BC/LC, was reviewed. RESULTS: In 32,824 women with LC, there were increased risks for synchronous BC in patients younger than age 50 years (hazard ratio, 5.80; 95% CI, 1.83 to 18.73), age 50 to 59 years (HR, 2.37; 95% CI, 1.02 to 5.54), and age 60 to 69 years (HR, 4.42; 95% CI, 1.91 to 10.2). In the 88,446 women with BC, there were increased risks for synchronous LC in patients age 40 to 59 years (HR, 5.86; 95% CI, 3.05 to 11.3) and older than 60 years (HR, 1.98; 95% CI, 1.04 to 3.77). In the 128-patient NTUH double LC/BC cohort, 77 (60%) had both cancers diagnosed within 5 years of each other. CONCLUSION: LC is associated with an increased risk for synchronous BC in Taiwan and vice versa. Radiotherapy might not be a major risk factor for LC in BC survivors. Etiology for double LC/BC deserves additional exploration and cross-racial genomic studies.

A CTLA-4 Antagonizing DNA Aptamer with Antitumor Effect.

The successful translation of cytotoxic T lymphocyte antigen-4 (CTLA-4) blockade has revolutionized the concept of cancer immunotherapy. Although monoclonal antibody therapeutics remain the mainstream in clinical practice, aptamers are synthetic oligonucleotides that encompass antibody-mimicking functions. Here, we report a novel high-affinity CTLA-4-antagonizing DNA aptamer (dissociation constant, 11.84 nM), aptCTLA-4, which was identified by cell-based SELEX and high-throughput sequencing. aptCTLA-4 is relatively stable in serum, promotes lymphocyte proliferation, and inhibits tumor growth in cell and animal models. Our study demonstrates the developmental pipeline of a functional CTLA-4-targeting aptamer and suggests a translational potential for aptCTLA-4.

A Novel PD-L1-targeting Antagonistic DNA Aptamer With Antitumor Effects.

The PD-1/PD-L1 axis is a major pathway involved in tumor immune evasion. Here, we report the novel PD-L1 antagonizing DNA aptamer (aptPD-L1) and demonstrate an integrated pipeline that expedites therapeutic aptamer development. Aptamer can exert antibody-mimic functions and is advantageous over antibody for its chemically synthetic nature, low immunogenicity, and efficient tissue penetration. Our results showed that aptPD-L1 blocked the binding between human PD-1 and PD-L1. Experiments using murine models showed that aptPD-L1 promoted in vitro lymphocyte proliferation and suppressed in vivo tumor growth without the induction of observable liver or renal toxicity. Analyses on the aptPD-L1-treated tumors further revealed elevated levels of infiltrating CD4+ and CD8+ T cells, intratumoral IL-2, TNF-α, interferon (IFN)-γ and the C-X-C motif chemokines, CXCL9 and CXCL10. The CD8+ T cells in the aptPD-L1-treated tumors had higher CXCR3 expression level compared to the random-sequence oligonucleotides-treated ones. Besides, the length and density of CD31+ intratumoral microvessels were significantly decreased in the aptPD-L1 treatment group. Collectively, our data suggested that aptPD-L1 helps T cell function restoration and modifies tumor microenvironment. These chemokines might orchestrate together to attract more T cells into the tumor tissues to form the positive amplification loop against tumor growth, indicating the translational potential of aptPD-L1 in cancer immunotherapy.

Association Between Parkinson Disease and Risk of Cancer in Taiwan.

IMPORTANCE: Parkinson disease (PD) has been reported to be associated with a general reduced risk of cancer. These studies were mainly carried out in Western populations and little was known about associations in East Asians. OBJECTIVE: To analyze the association between PD and risk of cancer. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, the data were obtained from the Taiwan National Health Insurance Research Database, which contained information on approximately 24.7 million insured individuals. The cohort included individuals with newly diagnosed as having PD between 2004 and 2010. An age- and sex-matched systematic random-sampling method was used for subject selection in the reference non-PD cohort. Multivariate Cox proportional hazard regression analysis was used to determine the effects of PD on the risks of cancer, as shown by hazard ratios (HRs) with 95% CIs. MAIN OUTCOMES AND MEASURES: The Taiwan Population Census and National Cancer Registry Databases were used to identify patients with cancer. The last follow-up date was December 31, 2012. RESULTS: In 62 023 patients with PD, the HR for all subsequent cancers combined was 1.58 (95% CI, 1.50-1.65). Of the 19 types of cancer, Parkinson disease was not associated with breast, ovarian, or thyroid cancers. Increased HRs were found in the remaining 16 cancers, including malignant brain tumors (HR, 3.42; 95% CI, 1.84-6.38), gastrointestinal tract cancers (esophageal [HR, 1.81; 95% CI, 1.28-2.57], stomach [HR, 1.59; 95% CI, 1.30-1.94], colorectal [HR, 1.47; 95% CI, 1.31-1.65], liver [HR, 1.89; 95% CI, 1.67-2.14]; gallbladder [HR, 1.73; 95% CI, 1.16-2.57], and pancreas [HR, 1.48; 95% CI, 1.09-2.02]) (P < .05 for all comparisons), lung cancers (HR, 1.56; 95% CI, 1.38-1.76), some hormone-related cancers (uterine [HR, 1.83; 95% CI, 1.12-3.01], cervical [HR, 1.36; 95% CI, 1.05-1.76], and prostate [HR, 1.80; 95% CI, 1.52-2.13; P < .05 for all comparisons), urinary tract cancers (kidney and bladder cancers; HRs, 1.59 and 1.99, respectively; P < .001 for both comparisons), lymphoma and/or leukemia (HR, 1.62; 95% CI, 1.31-2.01), melanoma (HR, 2.75; 95% CI, 1.35-5.59), and other skin cancers (HR, 1.81; 95% CI, 1.46-2.23). For hepatocellular carcinoma, the highest HR resided in the 50- to 59-year-old group (HR, 2.57; 95% CI, 1.7-3.89). CONCLUSIONS AND RELEVANCE: Our study concludes that PD is is associated with most cancers in Taiwan. Further studies are needed to clarify whether our findings can be applied to other East Asian populations. The differences between our study and most previous cohorts suggest the importance of ethnicity and environmental exposures in disease pathogenesis.

Gas7-deficient mouse reveals roles in motor function and muscle fiber composition during aging.

BACKGROUND: Growth arrest-specific gene 7 (Gas7) has previously been shown to be involved in neurite outgrowth in vitro; however, its actual role has yet to be determined. To investigate the physiological function of Gas7 in vivo, here we generated a Gas7-deficient mouse strain with a labile Gas7 mutant protein whose functions are similar to wild-type Gas7. METHODOLOGY/PRINCIPAL FINDINGS: Our data show that aged Gas7-deficient mice have motor activity defects due to decreases in the number of spinal motor neurons and in muscle strength, of which the latter may be caused by changes in muscle fiber composition as shown in the soleus. In cross sections of the soleus of Gas7-deficient mice, gross morphological features and levels of myosin heavy chain I (MHC I) and MHC II markers revealed significantly fewer fast fibers. In addition, we found that nerve terminal sprouting, which may be associated with slow and fast muscle fiber composition, was considerably reduced at neuromuscular junctions (NMJ) during aging. CONCLUSIONS/SIGNIFICANCE: These findings indicate that Gas7 is involved in motor neuron function associated with muscle strength maintenance.